Little panic. Need quick advice.

Having dinner party tonight and smoked a brisket. It was a 12 pounder and based on my past briskets it shouldíve taken around 15 hours. I put it in at 10 last night assuming itíd be done around 1 or 2 today. Then wrap towel and cooler for dinner. Well..... I woke up at 5 this morning and it was already at 196!! Only in 7 hours. I pulled it. Probed around with thermometer and it was 193-202 everywhere. Feels good and tender. Tasted a bite and itís fine. Just donít understand the extremely short cooking time. Did it at 225 like always. Only thing new was I tried a Costco PRIME brisket. Maybe being better marbled it cooked faster?? Anyway it now 6 AM and weíre eat at 7 tonight. What are your thoughts on what to do with it until then? Right now itís in the cooler wrapped. Donít think I should leave it there for 12 hours but not sure. Should I refrigerate it and reheat it somehow? If so, what do you recommend? Reheat in smokintex wrapped? In oven? Or can I somehow not refrigerate it for that long? Any help appreciated.
Thanks.

Thanks. Right now it’s still WTC and just picked it up and still hot. Might just leave it there until 4 like you suggested and then pop back in my 1400. I’ll check periodically and see if it remains hot in the cooler. If not I’ll pop it in the smoker at 170. It’s double butcher paper wrapped and then double foil wrapped. Would like to avoid refrigerating it and then heating back from cold but don’t want to serve guests spoiled meat either.

So how did it turn out? Also, for future reference if you preheat the cooler with hot water and use a couple towels to wrap the brisket I wouldn't worry about it as long as you keep your mits off the cooler and the lid closes tight. Your beer will stay cold for 12 hrs with the lid closed, same with your brisket in a heated cooler.